1. What is you home country/nationality?
2. Is mom married/have any other children (aside from you)
I hate too be the beared of bad news, but based on the sketchy information in your post, I wouldn't get my hopes up that your plan will become reality. Spouses can accompany international students and get a spousal open work permit, but I have NEVER heard of a parent qualifying to do so. I may be incorrect, but as far as I know, there is no provision that would allow anyone but a spouse to accompany an international student. As a matter of fact, depending on how many siblings (if any) you have in your home country or whether your mother is married and your father lives in the home country, you might have a very difficult time convincing them that you have sufficient ties to your home country (and your mother, in particular, would have an even more difficult time than you). Also, if you're counting on income that your mother would be earning here in Canada in order to finance your schooling and/or living expense, then you'll have an even more difficult time of it. Upon arrival in Canada, you must show that you have sufficient funds to pay for your schooling and expenses available THEN, and not your mother's earning POTENTIAL.
The way I see it, the only way your mother could even possible "accompany" you would be for her to apply on her own (completely separate from your study permit request) under an immigration provision she might qualify for, and based on what little we know about your specific situation, I can't think of way. A visitor visa would be limited to a maximum of six moinths, and would not permit your mother to work in Canada in any case.